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Upward Extensions -Permitted Development Rights

Changes will be implemented from the 1st August 2020.

Permitted Development for 2 storey roof extension

A new permitted development right will be introduced on 1st August 2020 that allows up to two additional storeys on existing flatted residential buildings.

To qualify the building must have been constructed between 1st July 1948 to 5th March 2018.

To qualify buildings must be:

– Free Standing and purpose built as flats.

– Three storeys and above; and

– Including the extension, not taller than 30 metres (not including plant).

– Floor to ceiling heights must not exceed those of the existing building or 3 metres in height.


  • Heritage buildings. Listed buildings or land within its curtilage.
  • Statues / monuments. Scheduled monuments or land within its curtilage
  • Military zones. Explosive storage areas.
  • Natural sites. Sites of special scientific interest.
  • Dangerous sites. A safety hazard area
  • Airfields.Land within 3 kilometres of the perimeter of an aerodrome.

What is needed to submit an application?

The legislation sets out the requirements in terms of what needs to be submitted to the Local Authority.

These comprise:

  1. A description of the proposed development along with any ancillary works.
  2. Plans that are scaled and show North, indicating the site and the proposed development.
  3. Proposed floor plans to scale showing the necessary detail to assess the application.
  4. A written statement that states the number of dwellings proposed and the number of existing.
  5. The addresses of all of the existing flats within the building.
  6. The developers contact details.
  7. A Flood Risk Assessment should this be required.
  8. We recommend submission of a daylight / sunlight assessment.
  9. Existing and proposed elevations.

We can help you

Unit One Architects can help building owners understand the planning policies around upward extensions and can submit Permitted Development applications.